This invention relates to a process for the treatment of allergic diseases of the respiratory passage and to cortecoid-containing inhalants useful therein.
It is known that corticoid-containing medicinal agents can be employed for the treatment of allergic diseases of the respiratory passages, such as, for example, rhinitis or bronchial asthma. However, the use of these drugs for the treatment of such diseases is not free from objection, in spite of their effectiveness, because corticoids used for this purpose often cause, in higher dosages and with long-term treatment, grave side effects in many cases, such as, for example, the so-called Cushing's syndrome (Brit. Med. J., 1966, 2, 796; and The Lancet, 1970, 733).
Compounds of Formula I hereinafter wherein R.sub.2 is a hydrogen atom are disclosed in Application Ser. No. 284,710, filed Aug. 30, 1972, now U.S. Pat. No. 3,824,260, and Application Ser. No. 460,905, filed Apr. 15, 1974, now U.S. Pat. No. 3,956,347 whose disclosures are incorporated by reference, as having topical anti-inflammatory activity but lacking systemic activity. Application Ser. No. 459,412 filed Apr. 9, 1974, now U.S. Pat. No. 3,906,095 is directed to pharmaceutical compositions comprising them adapted for topical administration and to the use thereof for the topical treatment of inflammation. Compounds of Formula I wherein R.sub.1 and R.sub.2 collectively are isopropylenedioxy are disclosed in Application Ser. No. 426,702, filed Dec. 20, 1973, now U.S. Pat. No. 3,919,421 having good topical anti-inflammatory activity but lacking systemic activity. There is no disclosure in these applications concerning the effectiveness of these corticoid steroids in the treatment of allergic diseases of the respiratory allergic diseases, the applications being directed to the treatment of diseases of the skin.
In order to mitigate the side effects occurring in the treatment of allergic diseases of the respiratory passages with corticoids, the practice was adapted to administer the corticoids in the form of aerosol inhalants, rather than orally as heretofore. See The Lancet, 163,147; Arch. Intern. Med., 115 [1965] 602; Brit. Med. J., 1972, 1, 585. Although it was possible to reduce the incidence of side effects with this form of application, it was impossible to eliminate the undesired side effects, because during inhaling a portion of the inhalant always enters the gastrointestinal tract and is absorbed systemically.
It is an object of the present invention to provide a method for the corticoid treatment of allergic diseases of the respiratory passages which is substantially free of undesired corticoid side-effects and to corticoid-containing inhalants useful therein.